What is a decontamination?

A decontamination involves is a series of procedures to kill and remove aquatic invasive species. Using hot water at low pressure at close range is the key step. The use of high pressure water on an aquatic-invasive- species-contaminated surface can be done afterwards to remove any residual attached AIS not removed during the initial clean, drain, dry and dispose steps.

When is a decontamination required?

Manitoba’s Aquatic Invasive Species Regulation under The Water Protection Act requires decontamination of:
  • water-related equipment that cannot be completely dried before placing it in another water body
  • watercraft removed from a control zone
  • water-related equipment removed from a control zone

Who can conduct a decontamination?

Decontamination can be conducted:

  • at a watercraft inspection station run by the Manitoba government
  • on your own, following the step-by-step procedure

Where can I go a get a decontamination?

Decontaminations can be performed by the Province of Manitoba’s Watercraft Inspection program. There is no fee for this service. Priority will be given to watercraft which has exited a control zone and is required by law to be decontaminated prior to launching into another water body. Courtesy decontaminations may be performed as time allows.

For up-to-date information on the location and times when the Watercraft Inspection program will be available, click here, or follow the Province of Manitoba’s Twitter page.

Step-by-step method to clean, drain, dry and decontaminate a watercraft, trailer or water-related equipment removed from an AIS invaded water body.

The most effective way to kill aquatic invasive species (AIS), including zebra mussels, is the use of extremely hot water. There is no need to use soap or chemicals. They are ineffective on zebra mussels and may cause damage to the aquatic environment.

The measures described here must be used on land away from another water body or drainage system such as a storm sewer or roadside ditch.

Do not attempt decontamination using a car wash facility. Water temperatures are inadequate and failure to kill zebra mussels during the decontamination process can result in spreading zebra mussels to the facility's infrastructure, to municipal infrastructure or to a water body through a drainage system such as a storm sewer.

Caution: Before beginning to clean or decontaminate water equipment, consult the owner's manual and the manufacturer’s specifications to make sure the equipment can withstand required temperatures and, pressures you may wish to use.

Watercraft, trailer, and water-related equipment may be decontaminated by :
  • using with very hot water (see step by step below)
  • OR
  • exposing the watercraft to temperatures below -10° C / 14° F for three consecutive days

Decontamination using hot water

This can be a three-step process.

  • Use extremely hot, low pressure water to kill zebra mussels and other AIS;
  • Use high pressure spray to physically remove any hard-to-reach or see AIS that may remain attached after the clean, drain, dry, and dispose steps; and
  • Allow everything to dry.

The decontamination process ensures compliance with federal and provincial AIS regulations prohibiting possessing of live or dead zebra mussels.

NOTE: Any watercraft, trailer or water-related equipment used in zebra mussel invaded water bodies, such as in the Central Control Zone, must be decontaminated with hot water before being placed into any other water body. High pressure hot water treatment is required as a second step if the watercraft, and water-related equipment has been moored or left in the water in a zebra mussel control zone for 12 hours or more. Use of high pressure ensures AIS have been completely removed from the watercraft. This ensures compliance with federal and provincial AIS regulations prohibiting possessing live or dead zebra mussels.

Step 1: Hot Water (thermal) Treatment

Hot water (thermal) treatment at low pressure is always the first step of a decontamination.  To ensure AIS is being killed then removed, these methods must be followed in the specified order below.

Never use a hot water together with a high pressure rinse first. AIS such as zebra mussel may not be successfully killed if using hot water at high pressure. This can lead to live zebra mussels entering un-invaded water bodies or access to  municipal drain infrastructure resulting in zebra mussel-clogged pipes.  

All surfaces that come into contact with a water body must be thoroughly decontaminated using low pressure, hot water. This includes the watercraft’s exterior (ex: hull, motor), interior (live wells) and any equipment such as anchors, PFDs, nets, float cushions/belts, chains, ropes, fenders as well as the trailer and backend of the motor vehicle.

NOTE: Consult your owner's manual and the manufacturer’s specifications before carrying out a decontamination to ensure the areas or items being treated can withstand the required temperatures and pressures.

There are two hot water (thermal) treatment options available depending on the item being treated –-Soak or rinse.

Soak (completely submerge) water-related equipment in a container for a minimum of 10 seconds in hot water at a minimum of 60° C (140° F) . Increase the contact time to 70 seconds for hard-to-reach or sensitive areas that do not receive direct contact with the hot water.

or

Rinse all surfaces of watercraft or water-related equipment that were exposed to the water body with hot water for a specific duration of time (see below). For a watercraft, focus on areas from the waterline down. Slowly and methodically thermally treat the watercraft or water-related equipment by ensuring all surfaces come in contact with the hot water.

A decontamination rinse, unless specified otherwise, is to be performed using low pressure (40-60 psi), hot water at a minimum of 60° C (140° F), ensuring at least 10 seconds of exposure to all surfaces. The nozzle where the water is exiting the hose can come into very close contact or direct contact with the surface being treated. The water must be sprayed at no more than 10 cm (4 inches) from the surface being treated.

Engine Decontamination
Hot Water Treatment

Option 1: Use an appropriate flushing attachment for your motor’s water intake/water intake port (motor muffs for outboard/outdrive motors; fake-a-lake for inboard/v-drive motors). Connect the attachment to a hot water source and use 60° C (140° F) water. Start the flow of water, then start and run your motor in neutral for 130 seconds to flush and kill any mussels in the engine cooling system. Monitor the engine temperature gauge to ensure the motor does not overheat. If water does not exit the telltale of the motor within 10 seconds, stop the motor. Recheck the muff seal, closely examine the water intake ports and check water intake screens for evidence of mussels or other blockage. Then try the motor flush again. If no water is seen emptying out of the telltale on the third try, contact a marine dealer for assistance. When completing the motor flush, shut down the engine first, then shut off the water supply. Disconnect all attachments and allow motor to drain.

Option 2: Fill a container (ex: a 44-gallon garbage container or flushing bag) with 60° C (140° F)  hot water and drop the lower unit of the motor into the container ensuring the water intakes are submerged in the water. Start and run your motor in neutral for 130 seconds. Remove motor from container and allow the motor to drain. Dispose of the water used for the motor flush on land away from any water body or drain.

Step 2: High-pressure Treatment

Pressure-washing your watercraft, trailer and water-related equipment can help to remove any remaining attached mussels that have been killed by the thermal treatment.

Use a power washer capable of producing 3,000 to 3,500 psi. Be sure to use a nozzle head that directs the water in a fan-like spray. A 40-degree flat fan spray is recommended. Do not use a pinpoint (zero-degree) spray, as this could damage the watercraft. Note that the use of high pressure may cause damage to some areas (e.g., gimbal area, transducers, motor, trim tabs) and that these should be avoided.

Spray the watercraft from 12-16 inches away at a 45° angle from the surface. With the flat fan spraying vertically, move the wand horizontally and systematically covering all areas of the hull and trailer that were exposed to water body. In one foot sections, typically starting just above the high water mark working towards the bottom centre line of the boat before moving to the next section and again starting from the top. Allow the spray to follow the length of the watercraft hull as you move from the front to the back of the watercraft. See figure below for placement, direction and movement of high-pressure wand.


NOTE: Consult your owner's manual and the manufacturer’s specifications before carrying out a decontamination to ensure the areas or items being treated can withstand the required temperatures and pressures.

Step 3: Drying

To further ensure the watercraft, trailer and water-related equipment are AIS free, allow everything to dry completely in the hot summer sun for at least 5 days. Drying times increase to 18 days in the spring and fall. Keep watercraft compartments open and allow water-related equipment to completely dry

How to decontaminate specific areas of the watercraft

Thermal treatments must be conducted on all surfaces that have come in contact with water including:

Internal Systems: Decontaminate by rinsing/flushing all internal systems of the watercraft or water-related equipment that were exposed to a water body, including the engine cooling system, air conditioning system or domestic water systems. Decontamination must be performed by flushing all internal compartments with minimum 50° C (122° F) water for 130 seconds.

Hard to Reach Areas: Thoroughly rinse all hard-to-reach areas and areas of the watercraft with low pressure water at a minimum of 60° C (140° F). Note that the use of high pressure may cause damage to some areas (ex: gimbal area, transducers, motor, trim tabs). A watercraft-friendly brush may be used with the hot water to help remove mussels from hard to reach areas. Using low pressure, maintain a contact time of at least 10 seconds with the nozzle where the water is exiting the hose can come into very close contact or preferably direct contact with the surface being treated. Direct contact to hot water is the most effective way to kill zebra mussels. For areas that do not receive direct contact with the hot water, increase the contact time to 70 seconds. Heating up the surrounding surfaces for a prolonged period of time around the area that cannot be directly contacted by the hot water can be effective for killing inaccessible AIS such as zebra mussels.

On-board Compartments: Decontaminate the live well, bait well, wet storage compartments, bilge areas by flushing the surface thoroughly with 50° C (120° F) water for 90 seconds, or filling compartment with 50° C (120° F) water and letting it stand for at least 130 seconds before draining.

Ballast Tanks: Decontaminate the ballast tanks by filling each ballast tank with maximum 50° C (120° F) water for a minimum of 130 seconds prior to draining.